341
CHAPTER 15 BUZZER OUTPUT
15.2 Configuration of the Buzzer Output

The buzzer output consists of the following two blocks:

Buzzer output selector

Buzzer register (BZCR)

Block Diagram of the Buzzer Output
Figure 15.2-1 Block Diagram of Buzzer Output
Buzzer output selector
The buzzer output selector is a circuit for selecting one of the four frequencies (square waves) output from
the time-base timer. The buzzer register (BZCR) sets it.
Buzzer register (BZCR)
The buzzer register (BZCR) is a register for setting the buzzer output frequency and enable the buzzer
output. When the BZCR register sets an output frequency (other than 000B), the buzzer output is enabled so
that the P37/BZ/PPG pin automatically becomes the buzzer output (BZ) pin. Even if the PPG pin has been
enabled, the BZ pin has higher priority.
FCH
BZ2 BZ1 BZ0
BZCR
P37/BZ/PPG
213/FCH
212/FCH
211/FCH
210/FCH
Internal data bus
From time-base timer Buzzer output
selector
Selector
output
Buzzer enable signal
Pin
: Oscillation frequency